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XIX, On the Immediate Principles of Human Excrements in the Healthy State. 
By W. Maecet, M.I)., F.C.S., Assistant Physician to the Westminster Hospital. 
Communicated by H. Bence Jones, M.H.., F.R.S. 
[Received February 23, — Eead March 12, 1857. 
In June 1854 I had the honour of communicating to the Koyal Society an account of 
some investigations I had undertaken respecting the composition of the excrements of 
man and animals ; since that time I have continued my researches on human excre- 
ments, and obtained further results which form the subject of the present paper, I 
have been most ably seconded in this work by my assistant, Mr, Feedeeick Dupee, Ph,D,, 
and have derived much valuable aid from his thorough knowledge of chemical and phy- 
sical science, • 
The method of investigation employed in this instance is similar to that which had 
been adopted on the former occasion ; alcohol and ether were again the principal means 
employed for conducting the analysis, chemical decompositions being thereby avoided 
and the constituents of excrements consequently obtained under the form of Immediate 
Principles. It will also be observed that in this case, for the purpose of extracting 
excretine, the alcohohc solution of excrements was in many instances not mixed with 
milk of hme, which simphfied materially the operations and increased the interest of the 
investigation. 
The results obtained are as follows : — 
1, Margarate of lime, phosphate of lime, and margarate of magnesia were discovered 
to be three immediate principles of human evacuations, 
2, I found a new and simple method for obtaining excretine, and its chemical for- 
mula has been estabhshed, 
3, The fact that vegetable food increases the presence of margaric acid in excrements 
has been contu’med, 
4, The existence of a comparatively large quantity of cholesterine in the spleen, which 
I had mentioned as probable, has been confirmed *. 
When healthy human evacuations are exhausted with boiling alcohol an extract is 
obtained, which, on coohng, leaves a deposit. This deposit was examined as follows : — 
The dark alcoholic solution being decanted, the residue was thrown upon a filter and 
washed thoroughly, first with cold and then with boiling alcohol. The boiling alcoholic 
solution, on cooling, yielded more or less of a peculiar substance, in the form of a fight 
granular precipitate, which has been alluded to in my previous communication. The 
* I introduce here this result, having alluded to the subject in my previous communication. 
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